Mid-twenty-first century global wave climate projections: Results from a dynamic CMIP5 based ensemble

Abstract Wind-generated waves at the sea surface are of outstanding importance for both their practical relevance in many aspects, such as coastal erosion, protection, or safety of navigation, and for their scientific relevance in modifying fluxes at the air–sea interface. So far, long-term changes in ocean wave climate have been studied mostly from a regional perspective with global dynamical studies emerging only recently. Here a global wave climate study is presented, in which a global wave model [Wave Ocean Model (WAM)] is driven by atmospheric forcing from a global climate model (ECHAM5) for present-day and potential future climate conditions represented by the Intergovernmental Panel for Climate Change (IPCC) A1B emission scenario. It is found that changes in mean and extreme wave climate toward the end of the twenty-first century are small to moderate, with the largest signals being a poleward shift in the annual mean and extreme significant wave heights in the midlatitudes of both hemispheres, more pronounced in the Southern Hemisphere and most likely associated with a corresponding shift in midlatitude storm tracks. These changes are broadly consistent with results from the few studies available so far. The projected changes in the mean wave periods, associated with the changes in the wave climate in the middle to high latitudes, are also shown, revealing a moderate increase in the equatorial eastern side of the ocean basins. This study presents a step forward toward a larger ensemble of global wave climate projections required to better assess robustness and uncertainty of potential future wave climate change.

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Ocean Swells along the Global Coastlines and Their Climate Projections for the Twenty-First Century

Journal of Climate ◽

10.1175/jcli-d-19-0216.1 ◽

2020 ◽

Vol 33 (1) ◽

pp. 185-199

Author(s):

Angel Amores ◽

Marta Marcos

Keyword(s):

Southern Hemisphere ◽

Climate Models ◽

Wind Waves ◽

Wave Model ◽

Wave Climate ◽

First Century ◽

Change Scenario ◽

Climate Projections ◽

Wave Hindcast ◽

Twenty First Century

AbstractRemotely generated swell waves are the dominant contributor of the coastal wind-wave climate along most of the world coastlines. In this work we describe the characteristics of swells from a coastal perspective. We identify the main regions of formation of swell waves at present and during the late twenty-first century under the RCP8.5 emissions/climate change scenario. We have applied an algorithm that allows one to unequivocally differentiate the swell component from the local wind-waves for a global wave hindcast and for eight CMIP5 state-of-the-art wave model climate projections. We have identified four different regions of swell formation, two in each hemisphere, with the Southern Ocean being by far the main region of swell generation. By the end of this century, the number of swell events generated in the Northern Hemisphere is expected to decrease while the opposite is projected to occur in the Southern Hemisphere. The increase in the Southern Hemisphere is directly associated with a poleward movement and intensification of the wind belts projected by atmospheric climate models.

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Bias-Corrected CMIP5-Derived Single-Forcing Future Wind-Wave Climate Projections toward the End of the Twenty-First Century

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-19-0297.1 ◽

2020 ◽

Vol 59 (9) ◽

pp. 1393-1414

Author(s):

Gil Lemos ◽

Alvaro Semedo ◽

Mikhail Dobrynin ◽

Melisa Menendez ◽

Pedro M. A. Miranda

Keyword(s):

Bias Correction ◽

Correction Method ◽

Wave Climate ◽

First Century ◽

Climate Projections ◽

Wave Direction ◽

Quantile Mapping ◽

Bias Correction Method ◽

Twenty First Century ◽

Projected Changes

AbstractA quantile-based bias-correction method is applied to a seven-member dynamic ensemble of global wave climate simulations with the aim of reducing the significant wave height HS, mean wave period Tm, and mean wave direction (MWD) biases, in comparison with the ERA5 reanalysis. The corresponding projected changes toward the end of the twenty-first century are assessed. Seven CMIP5 EC-EARTH runs (single forcing) were used to force seven wave model (WAM) realizations (single model), following the RCP8.5 scenario (single scenario). The biases for the 1979–2005 reference period (present climate) are corrected using the empirical Gumbel quantile mapping and empirical quantile mapping methods. The same bias-correction parameters are applied to the HS, Tm (and wave energy flux Pw), and MWD future climate projections for the 2081–2100 period. The bias-corrected projected changes show increases in the annual mean HS (14%), Tm (6.5%), and Pw (30%) in the Southern Hemisphere and decreases in the Northern Hemisphere (mainly in the North Atlantic Ocean) that are more pronounced during local winter. For the upper quantiles, the bias-corrected projected changes are more striking during local summer, up to 120%, for Pw. After bias correction, the magnitude of the HS, Tm, and Pw original projected changes has generally increased. These results, albeit consistent with recent studies, show the relevance of a quantile-based bias-correction method in the estimation of the future projected changes in swave climate that is able to deal with the misrepresentation of extreme phenomena, especially along the tropical and subtropical latitudes.

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Quantifying Sources of Uncertainty in Projections of Future Climate*

Journal of Climate ◽

10.1175/jcli-d-14-00265.1 ◽

2014 ◽

Vol 27 (23) ◽

pp. 8793-8808 ◽

Cited By ~ 38

Author(s):

Paul J. Northrop ◽

Richard E. Chandler

Keyword(s):

General Circulation ◽

Climate Model ◽

Internal Variability ◽

Future Climate ◽

First Century ◽

Climate Projections ◽

Large Contribution ◽

Sources Of Uncertainty ◽

Twenty First Century ◽

Emissions Scenario

Abstract A simple statistical model is used to partition uncertainty from different sources, in projections of future climate from multimodel ensembles. Three major sources of uncertainty are considered: the choice of climate model, the choice of emissions scenario, and the internal variability of the modeled climate system. The relative contributions of these sources are quantified for mid- and late-twenty-first-century climate projections, using data from 23 coupled atmosphere–ocean general circulation models obtained from phase 3 of the Coupled Model Intercomparison Project (CMIP3). Similar investigations have been carried out recently by other authors but within a statistical framework for which the unbalanced nature of the data and the small number (three) of scenarios involved are potentially problematic. Here, a Bayesian analysis is used to overcome these difficulties. Global and regional analyses of surface air temperature and precipitation are performed. It is found that the relative contributions to uncertainty depend on the climate variable considered, as well as the region and time horizon. As expected, the uncertainty due to the choice of emissions scenario becomes more important toward the end of the twenty-first century. However, for midcentury temperature, model internal variability makes a large contribution in high-latitude regions. For midcentury precipitation, model internal variability is even more important and this persists in some regions into the late century. Implications for the design of climate model experiments are discussed.

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Projected twenty-first-century changes in the Central American mid-summer drought using statistically downscaled climate projections

Regional Environmental Change ◽

10.1007/s10113-017-1177-6 ◽

2017 ◽

Vol 17 (8) ◽

pp. 2421-2432 ◽

Cited By ~ 13

Author(s):

Edwin P. Maurer ◽

Nicholas Roby ◽

Iris T. Stewart-Frey ◽

Christopher M. Bacon

Keyword(s):

First Century ◽

Central American ◽

Climate Projections ◽

Summer Drought ◽

Twenty First Century

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Twenty-First-Century Snowfall and Snowpack Changes over the Southern California Mountains

Journal of Climate ◽

10.1175/jcli-d-15-0199.1 ◽

2015 ◽

Vol 29 (1) ◽

pp. 91-110 ◽

Cited By ~ 28

Author(s):

Fengpeng Sun ◽

Alex Hall ◽

Marla Schwartz ◽

Daniel B. Walton ◽

Neil Berg

Keyword(s):

General Circulation ◽

Southern California ◽

Snow Water Equivalent ◽

Coupled Model ◽

General Circulation Models ◽

First Century ◽

Climate Projections ◽

Rcp Scenarios ◽

Ensemble Mean ◽

Twenty First Century

Abstract Future snowfall and snowpack changes over the mountains of Southern California are projected using a new hybrid dynamical–statistical framework. Output from all general circulation models (GCMs) in phase 5 of the Coupled Model Intercomparison Project archive is downscaled to 2-km resolution over the region. Variables pertaining to snow are analyzed for the middle (2041–60) and end (2081–2100) of the twenty-first century under two representative concentration pathway (RCP) scenarios: RCP8.5 (business as usual) and RCP2.6 (mitigation). These four sets of projections are compared with a baseline reconstruction of climate from 1981 to 2000. For both future time slices and scenarios, ensemble-mean total winter snowfall loss is widespread. By the mid-twenty-first century under RCP8.5, ensemble-mean winter snowfall is about 70% of baseline, whereas the corresponding value for RCP2.6 is somewhat higher (about 80% of baseline). By the end of the century, however, the two scenarios diverge significantly. Under RCP8.5, snowfall sees a dramatic further decline; 2081–2100 totals are only about half of baseline totals. Under RCP2.6, only a negligible further reduction from midcentury snowfall totals is seen. Because of the spread in the GCM climate projections, these figures are all associated with large intermodel uncertainty. Snowpack on the ground, as represented by 1 April snow water equivalent is also assessed. Because of enhanced snowmelt, the loss seen in snowpack is generally 50% greater than that seen in winter snowfall. By midcentury under RCP8.5, warming-accelerated spring snowmelt leads to snow-free dates that are about 1–3 weeks earlier than in the baseline period.

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North Atlantic Ocean Wave Climate Change Scenarios for the Twenty-First Century

Journal of Climate ◽

10.1175/1520-0442(2004)017<2368:naowcc>2.0.co;2 ◽

2004 ◽

Vol 17 (12) ◽

pp. 2368-2383 ◽

Cited By ~ 123

Author(s):

Xiaolan L. Wang ◽

Francis W. Zwiers ◽

Val R. Swail

Keyword(s):

Climate Change ◽

Atlantic Ocean ◽

North Atlantic ◽

North Atlantic Ocean ◽

Wave Climate ◽

First Century ◽

Ocean Wave ◽

Climate Change Scenarios ◽

Twenty First Century ◽

Ocean Wave Climate

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Physical Mechanisms Related to Climate-Induced Drying of Two Semiarid Watersheds in the Southwestern United States

Journal of Hydrometeorology ◽

10.1175/jhm-d-13-0106.1 ◽

2014 ◽

Vol 15 (4) ◽

pp. 1404-1418 ◽

Cited By ~ 6

Author(s):

Seshadri Rajagopal ◽

Francina Dominguez ◽

Hoshin V. Gupta ◽

Peter A. Troch ◽

Christopher L. Castro

Keyword(s):

United States ◽

The United States ◽

Hydrologic Model ◽

First Century ◽

Climate Projections ◽

Southwestern United States ◽

Study Region ◽

Model Average ◽

Basin Scale ◽

Twenty First Century

Abstract Water managers across the United States face the need to make informed policy decisions regarding long-term impacts of climate change on water resources. To provide a scientifically informed basis for this, the evolution of important components of the basin-scale water balance through the end of the twenty-first century is estimated. Bias-corrected and spatially downscaled climate projections, from phase 3 of the Coupled Model Intercomparison Project (CMIP3) of the World Climate Research Programme, were used to drive a spatially distributed Variable Infiltration Capacity (VIC) model of hydrologic processes in the Salt–Verde basin in the southwestern United States. From the suite of CMIP3 models, the authors select a five-model subset, including three that best reproduce the historical climatology for the study region, plus two others to represent wetter and drier than model average conditions, so as to represent the range of GCM prediction uncertainty. For each GCM, data for three emission scenarios (A1B, A2, and B1) were used to drive the hydrologic model into the future. The projections of this model ensemble indicate a statistically significant 25% decrease in streamflow by the end of the twenty-first century. The primary cause for this change is due to projected decreases in winter precipitation accompanied by significant (temperature driven) reductions in storage of snow and increased winter evaporation. The results show that water management in central Arizona is highly likely to be impacted by changes in regional climate.

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